(1) Field of the Invention
This invention concerns a cylinder driving system for controlling the drive of a load by balance cylinders and a drive cylinder.
(2) Description of the Prior Art
In a usual cylinder driving system employed so far, double-acting cylinders in large diameter capable of producing greater acting force than the weight of load have been used in order to drive heavy weight loads. It required, however, an extremely great amount of air charged and discharged to and from the cylinder in order to drive the load. Further, since the amount of air charged and discharged to and from the cylinder can not be controlled accurately in the use of the large diameter cylinder, it resulted in various drawbacks also in the control of driving operation such as imbalanced driving property when the upward starting is slow and downward starting is fast, difficulty in the smooth deceleration in the midway of the stroke being accompanied with vibrating rebounding action, violent collisions at the stroke ends, damping vibrations occuring upon emergency stop and the like.